score = int(input('请输入学生成绩：'))
if score >= 90:
    print("学生成绩为A")
elif score >= 80 and score < 90:
    print("学生成绩为B")
elif score >= 70 and score < 80:
    print("学生成绩为C")
elif score >= 60 and score < 70:
    print("学生成绩为D")
elif score >= 0 and score <60:
    print("学生成绩为F")

print("计科1814-34-郭文聪")